#2 The centre-back pairing
Manchester United had quite an affirming defence at the start of the new season but have been struggling in their own final third lately. Ever since Eric Bailly got injured in December, Jose Mourinho has shuffled his defence regularly.
He has played various permutations of Victor Lindelof, Chris Smalling and Phil Jones in the defence and preferred the duo of Smalling and Jones more often. In those three players, United have defenders who are the perfect personification of the chasm between good and great centre-backs.
United have been looking shaky at the back of late this season. While facing the opposition who fancy their chances on the ball, the back-line of United seem vulnerable. Eric Bailly and Marcos Rojo's absence has turned this defence leaky.
Eric Bailly, is the focal point of United's defence at the moment. Jose needs a defender like Toby Alderweireld who can ease the pressure off Ivorian and strengthen the back-line.